The sleep bank: what you do during the day matters

Have you ever spent the day feeling absolutely exhausted, only to climb into bed and suddenly find yourself wide awake?

It's frustrating, isn't it? You've been looking forward to getting into bed all evening, convinced you'll fall asleep the moment your head hits the pillow. Yet there you are, staring at the ceiling, wondering why your brain and body aren't cooperating.

One thing I find fascinating about sleep is something called sleep pressure, and I like to think of it as a sleep bank. Understanding how it works can make a real difference to the way you think about sleep.

What exactly is sleep pressure?

From the moment you wake up in the morning, your body starts building up a natural drive to sleep. The longer you're awake, the stronger that drive generally becomes. This is known as sleep pressure, and it's one of the main systems that regulates when we feel sleepy.

During waking hours, a substance called adenosine builds up in the brain. This is one of the chemical signals associated with increasing sleep pressure. When we sleep, that pressure gradually reduces, helping us wake up feeling refreshed and ready for another day.

It's a bit like filling a bank throughout the day, except instead of putting money in, you're building up your body's natural need for sleep. And here's the interesting part. Some of the things we do during the day can influence how much sleep pressure we've built up by bedtime.

Are you helping or hindering your sleep bank?

Let's imagine you've had a particularly poor night's sleep. You're exhausted, so you decide to lie in a little. Later, you settle on the sofa for a nap. By early evening, you're feeling tired again, so you decide to go to bed an hour earlier than usual.

All perfectly understandable. But here's the problem. By sleeping later, napping during the day, and going to bed earlier, you may reduce the sleep pressure you have when you actually want to sleep. You might feel physically tired, but your body hasn't necessarily built up enough drive for sustained sleep. 

And so the cycle continues. You struggle to sleep, compensate the following day, and then wonder why you're wide awake again the next night. This pattern can develop surprisingly easily.

Five ways to help build your sleep pressure

The good news is that you can do some relatively simple things to support your body's natural sleep drive:

1. Get up at roughly the same time each morning

I know, particularly after a terrible night's sleep, the temptation to stay in bed is enormous. But keeping a reasonably consistent wake-up time helps regulate your body clock and gives your sleep pressure a more predictable chance to build throughout the day.

2. Keep yourself active

You don't need to run a marathon or spend hours in the gym! Walking, gardening, cycling, swimming or whatever form of movement you enjoy can support better sleep. Exercise doesn't simply fill your sleep bank like putting coins into a jar, but regular physical activity is associated with improved sleep quality. And if you can get outside in daylight, even better, because natural light helps regulate your body clock.

3. Be mindful of daytime naps

There's nothing inherently wrong with napping, and for some people, it's genuinely beneficial. However, if you're already struggling to sleep at night, particularly if you have insomnia, daytime naps may reduce the sleep pressure you've been building. A long afternoon nap can sometimes make it harder to fall asleep at your usual bedtime.

4. Don't automatically go to bed earlier because you're tired

This is one that often surprises people. If you've slept badly, going to bed earlier might seem the obvious solution. But spending extra time in bed when you're not sleepy can mean more time lying awake, getting frustrated, and worrying about sleep. And that's exactly what we're trying to avoid.

5. Learn the difference between being tired and being sleepy

This is such an important distinction. You can feel absolutely exhausted, mentally drained and desperate for rest without actually being sleepy. Sleepiness is that lovely feeling when your eyelids become heavy, you start yawning, and you can feel yourself drifting off. Tiredness, on the other hand, can simply mean you're fatigued. Learning to recognise the difference can help you decide when to go to bed.

What if my sleep bank is full and I still can't sleep?

This is where things get particularly interesting, because sleep pressure is only part of the picture. Your body clock also helps determine when your body is ready for sleep and wakefulness. And then there's something else. Your mind.

You can have plenty of sleep pressure, be genuinely sleepy, and still find yourself wide awake because your mind has decided that bedtime is the perfect opportunity to think about absolutely everything. Tomorrow's meeting. Something you said last Tuesday. Whether you've remembered to pay a bill. Sound familiar?

For some people, sleep itself becomes a source of anxiety. They start watching the clock, calculating how many hours they've got left and worrying about how they'll cope the following day.

The harder they try to sleep, the more elusive it becomes. This is why simply telling someone to go to bed earlier, avoid caffeine or put their phone away isn't always enough. Sometimes we need to look at the thoughts, feelings and habits that have developed around sleep.

Where does hypnotherapy fit in?

When sleep becomes something we worry about, bedtime can start to feel less like an opportunity to rest and more like a nightly battle. We become increasingly focused on whether we'll sleep, how long it will take and how exhausted we'll feel tomorrow. Unfortunately, all that worrying can leave us feeling even more alert when we're trying to switch off.

Hypnotherapy may help by supporting people in exploring their relationship with sleep, practising relaxation, and addressing some of the anxious thoughts associated with bedtime.

It isn't about making someone fall asleep through hypnosis. Instead, it helps reduce the mental struggle that can develop around sleep. Although research into hypnotherapy for insomnia is still limited, it may be a useful complementary approach for some people, particularly when anxiety and worry are contributing to their difficulties.

Better sleep starts long before bedtime

One of the most important things to understand is that sleep is a natural biological process, not something you can force yourself to do. You can create the right conditions, build healthy habits, and learn to reduce the worry around it, but you cannot make yourself fall asleep through sheer determination.

And while sleep pressure is an important part of the picture, it's not the only factor. Stress, health conditions, medication and your body clock can all influence how well you sleep.

If sleep difficulties persist or affect your daily life, it's worth speaking to a healthcare professional. Cognitive behavioural therapy for insomnia (CBT-I) is a recommended first-line treatment for chronic insomnia.

So tonight, rather than focusing entirely on what happens when your head hits the pillow, think about what you've been doing since you got out of bed this morning. Because better sleep doesn't necessarily begin at bedtime. Very often, it begins the moment you wake up.